Advantage of actual femoral head-neck measurement in limb-length equalization in the hip hemiarthroplasty

Abstract

Objective To probe the advantage of actual femoral head-neck measurement in limb-length equalization in the hip hemiarthroplasty.Methods From January 2008 to July 2010,30 cases received actual femoral head-neck measurement in hip hemiarthroplasty.They were 9 males and 21 females,71.2 years of age on average.The matched control group included 60 cases receiving conventional hip hemiarthroplasty from July 2003 to October 2007.They were 17 males and 43 females,68.5 years of age on average.The actual femoral head-neck measurement was used to decide the size of implant during the operation.The 2 groups were compared in terms of the reduced length of the affected limb on the preoperative X-ray film,the length discrepancy on the postoperative X-ray film and hip Harris score.Results In theactual measurement group,there were 21 excellent cases regarding length discrepancy (within 5 nn),7 good cases (6 to 10 mm) and 2 fair cases (11 to 15 mm),with an excellent to good rate of 93.3％,while in the control group there were 19 excellent cases,30 good cases,9 fair cases and 2 bad cases (over 15 mm),with an excellent to good rate of 82.5％.The difference between the 2 groups was statistically significant (x2 =8.350,P =0.008).Twenty-seven cases in the actual measurement group obtained an average follow-up of 15.3 months (from 12 to 24 months) while 56 cases in the control group obtained an average follow-up of 20.5 months (from 13 to 35 months).In terms of the hip Harris score at the last follow-up,the actual measurement group had 20 excellent cases,5 good cases and 2 fair cases while the control group had 29 excellent cases,18 good cases,7 fair cases and 2 bad cases.There was a significant difference regarding the excellent to good rate (91.7％ versus 83.9％) between the 2 groups (x2 =6.451,P =0.017).Conclusion In the hip hemiarthroplasty,the actual femoral head-neck measurement is a simple but reliable method to control the length discrepancy more accurately than the conventional method. Key words: Arthroplasty, replacement, hip; Lower extremity; Research design